]> git.kernelconcepts.de Git - karo-tx-linux.git/commitdiff
i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver
authorMasahiro Yamada <yamada.masahiro@socionext.com>
Fri, 23 Oct 2015 10:52:00 +0000 (19:52 +0900)
committerWolfram Sang <wsa@the-dreams.de>
Fri, 23 Oct 2015 11:44:07 +0000 (13:44 +0200)
Add support for on-chip I2C controller used on newer UniPhier SoCs
such as PH1-Pro4, PH1-Pro5, etc.  This adapter is equipped with
8-depth TX/RX FIFOs.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Documentation/devicetree/bindings/i2c/i2c-uniphier-f.txt [new file with mode: 0644]
drivers/i2c/busses/Kconfig
drivers/i2c/busses/Makefile
drivers/i2c/busses/i2c-uniphier-f.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/i2c/i2c-uniphier-f.txt b/Documentation/devicetree/bindings/i2c/i2c-uniphier-f.txt
new file mode 100644 (file)
index 0000000..27fc6f8
--- /dev/null
@@ -0,0 +1,25 @@
+UniPhier I2C controller (FIFO-builtin)
+
+Required properties:
+- compatible: should be "socionext,uniphier-fi2c".
+- #address-cells: should be 1.
+- #size-cells: should be 0.
+- reg: offset and length of the register set for the device.
+- interrupts: a single interrupt specifier.
+- clocks: phandle to the input clock.
+
+Optional properties:
+- clock-frequency: desired I2C bus frequency in Hz.  The maximum supported
+  value is 400000.  Defaults to 100000 if not specified.
+
+Examples:
+
+       i2c0: i2c@58780000 {
+               compatible = "socionext,uniphier-fi2c";
+               reg = <0x58780000 0x80>;
+               #address-cells = <1>;
+               #size-cells = <0>;
+               interrupts = <0 41 4>;
+               clocks = <&i2c_clk>;
+               clock-frequency = <100000>;
+       };
index 4dcbed48f9e176516b804e3c0911743790486eb5..3e6e3bd358674420cbc1fbc6815468270cfe51dd 100644 (file)
@@ -910,6 +910,14 @@ config I2C_UNIPHIER
          the UniPhier FIFO-less I2C interface embedded in PH1-LD4, PH1-sLD8,
          or older UniPhier SoCs.
 
+config I2C_UNIPHIER_F
+       tristate "UniPhier FIFO-builtin I2C controller"
+       depends on ARCH_UNIPHIER
+       help
+         If you say yes to this option, support will be included for
+         the UniPhier FIFO-builtin I2C interface embedded in PH1-Pro4,
+         PH1-Pro5, or newer UniPhier SoCs.
+
 config I2C_VERSATILE
        tristate "ARM Versatile/Realview I2C bus support"
        depends on ARCH_VERSATILE || ARCH_REALVIEW || ARCH_VEXPRESS
index f9f09028568137d9af67f6495e8fe586b5223c19..37f2819b4560b0e0947b74c214f5c5a0952bc0ae 100644 (file)
@@ -88,6 +88,7 @@ obj-$(CONFIG_I2C_STU300)      += i2c-stu300.o
 obj-$(CONFIG_I2C_SUN6I_P2WI)   += i2c-sun6i-p2wi.o
 obj-$(CONFIG_I2C_TEGRA)                += i2c-tegra.o
 obj-$(CONFIG_I2C_UNIPHIER)     += i2c-uniphier.o
+obj-$(CONFIG_I2C_UNIPHIER_F)   += i2c-uniphier-f.o
 obj-$(CONFIG_I2C_VERSATILE)    += i2c-versatile.o
 obj-$(CONFIG_I2C_WMT)          += i2c-wmt.o
 obj-$(CONFIG_I2C_OCTEON)       += i2c-octeon.o
diff --git a/drivers/i2c/busses/i2c-uniphier-f.c b/drivers/i2c/busses/i2c-uniphier-f.c
new file mode 100644 (file)
index 0000000..e8d03bc
--- /dev/null
@@ -0,0 +1,584 @@
+/*
+ * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#define UNIPHIER_FI2C_CR       0x00    /* control register */
+#define     UNIPHIER_FI2C_CR_MST       BIT(3)  /* master mode */
+#define     UNIPHIER_FI2C_CR_STA       BIT(2)  /* start condition */
+#define     UNIPHIER_FI2C_CR_STO       BIT(1)  /* stop condition */
+#define     UNIPHIER_FI2C_CR_NACK      BIT(0)  /* do not return ACK */
+#define UNIPHIER_FI2C_DTTX     0x04    /* TX FIFO */
+#define     UNIPHIER_FI2C_DTTX_CMD     BIT(8)  /* send command (slave addr) */
+#define     UNIPHIER_FI2C_DTTX_RD      BIT(0)  /* read transaction */
+#define UNIPHIER_FI2C_DTRX     0x04    /* RX FIFO */
+#define UNIPHIER_FI2C_SLAD     0x0c    /* slave address */
+#define UNIPHIER_FI2C_CYC      0x10    /* clock cycle control */
+#define UNIPHIER_FI2C_LCTL     0x14    /* clock low period control */
+#define UNIPHIER_FI2C_SSUT     0x18    /* restart/stop setup time control */
+#define UNIPHIER_FI2C_DSUT     0x1c    /* data setup time control */
+#define UNIPHIER_FI2C_INT      0x20    /* interrupt status */
+#define UNIPHIER_FI2C_IE       0x24    /* interrupt enable */
+#define UNIPHIER_FI2C_IC       0x28    /* interrupt clear */
+#define     UNIPHIER_FI2C_INT_TE       BIT(9)  /* TX FIFO empty */
+#define     UNIPHIER_FI2C_INT_RF       BIT(8)  /* RX FIFO full */
+#define     UNIPHIER_FI2C_INT_TC       BIT(7)  /* send complete (STOP) */
+#define     UNIPHIER_FI2C_INT_RC       BIT(6)  /* receive complete (STOP) */
+#define     UNIPHIER_FI2C_INT_TB       BIT(5)  /* sent specified bytes */
+#define     UNIPHIER_FI2C_INT_RB       BIT(4)  /* received specified bytes */
+#define     UNIPHIER_FI2C_INT_NA       BIT(2)  /* no ACK */
+#define     UNIPHIER_FI2C_INT_AL       BIT(1)  /* arbitration lost */
+#define UNIPHIER_FI2C_SR       0x2c    /* status register */
+#define     UNIPHIER_FI2C_SR_DB                BIT(12) /* device busy */
+#define     UNIPHIER_FI2C_SR_STS       BIT(11) /* stop condition detected */
+#define     UNIPHIER_FI2C_SR_BB                BIT(8)  /* bus busy */
+#define     UNIPHIER_FI2C_SR_RFF       BIT(3)  /* RX FIFO full */
+#define     UNIPHIER_FI2C_SR_RNE       BIT(2)  /* RX FIFO not empty */
+#define     UNIPHIER_FI2C_SR_TNF       BIT(1)  /* TX FIFO not full */
+#define     UNIPHIER_FI2C_SR_TFE       BIT(0)  /* TX FIFO empty */
+#define UNIPHIER_FI2C_RST      0x34    /* reset control */
+#define     UNIPHIER_FI2C_RST_TBRST    BIT(2)  /* clear TX FIFO */
+#define     UNIPHIER_FI2C_RST_RBRST    BIT(1)  /* clear RX FIFO */
+#define     UNIPHIER_FI2C_RST_RST      BIT(0)  /* forcible bus reset */
+#define UNIPHIER_FI2C_BM       0x38    /* bus monitor */
+#define     UNIPHIER_FI2C_BM_SDAO      BIT(3)  /* output for SDA line */
+#define     UNIPHIER_FI2C_BM_SDAS      BIT(2)  /* readback of SDA line */
+#define     UNIPHIER_FI2C_BM_SCLO      BIT(1)  /* output for SCL line */
+#define     UNIPHIER_FI2C_BM_SCLS      BIT(0)  /* readback of SCL line */
+#define UNIPHIER_FI2C_NOISE    0x3c    /* noise filter control */
+#define UNIPHIER_FI2C_TBC      0x40    /* TX byte count setting */
+#define UNIPHIER_FI2C_RBC      0x44    /* RX byte count setting */
+#define UNIPHIER_FI2C_TBCM     0x48    /* TX byte count monitor */
+#define UNIPHIER_FI2C_RBCM     0x4c    /* RX byte count monitor */
+#define UNIPHIER_FI2C_BRST     0x50    /* bus reset */
+#define     UNIPHIER_FI2C_BRST_FOEN    BIT(1)  /* normal operation */
+#define     UNIPHIER_FI2C_BRST_RSCL    BIT(0)  /* release SCL */
+
+#define UNIPHIER_FI2C_INT_FAULTS       \
+                               (UNIPHIER_FI2C_INT_NA | UNIPHIER_FI2C_INT_AL)
+#define UNIPHIER_FI2C_INT_STOP         \
+                               (UNIPHIER_FI2C_INT_TC | UNIPHIER_FI2C_INT_RC)
+
+#define UNIPHIER_FI2C_RD               BIT(0)
+#define UNIPHIER_FI2C_STOP             BIT(1)
+#define UNIPHIER_FI2C_MANUAL_NACK      BIT(2)
+#define UNIPHIER_FI2C_BYTE_WISE                BIT(3)
+#define UNIPHIER_FI2C_DEFER_STOP_COMP  BIT(4)
+
+#define UNIPHIER_FI2C_DEFAULT_SPEED    100000
+#define UNIPHIER_FI2C_MAX_SPEED                400000
+#define UNIPHIER_FI2C_FIFO_SIZE                8
+
+struct uniphier_fi2c_priv {
+       struct completion comp;
+       struct i2c_adapter adap;
+       void __iomem *membase;
+       struct clk *clk;
+       unsigned int len;
+       u8 *buf;
+       u32 enabled_irqs;
+       int error;
+       unsigned int flags;
+       unsigned int busy_cnt;
+};
+
+static void uniphier_fi2c_fill_txfifo(struct uniphier_fi2c_priv *priv,
+                                     bool first)
+{
+       int fifo_space = UNIPHIER_FI2C_FIFO_SIZE;
+
+       /*
+        * TX-FIFO stores slave address in it for the first access.
+        * Decrement the counter.
+        */
+       if (first)
+               fifo_space--;
+
+       while (priv->len) {
+               if (fifo_space-- <= 0)
+                       break;
+
+               dev_dbg(&priv->adap.dev, "write data: %02x\n", *priv->buf);
+               writel(*priv->buf++, priv->membase + UNIPHIER_FI2C_DTTX);
+               priv->len--;
+       }
+}
+
+static void uniphier_fi2c_drain_rxfifo(struct uniphier_fi2c_priv *priv)
+{
+       int fifo_left = priv->flags & UNIPHIER_FI2C_BYTE_WISE ?
+                                               1 : UNIPHIER_FI2C_FIFO_SIZE;
+
+       while (priv->len) {
+               if (fifo_left-- <= 0)
+                       break;
+
+               *priv->buf++ = readl(priv->membase + UNIPHIER_FI2C_DTRX);
+               dev_dbg(&priv->adap.dev, "read data: %02x\n", priv->buf[-1]);
+               priv->len--;
+       }
+}
+
+static void uniphier_fi2c_set_irqs(struct uniphier_fi2c_priv *priv)
+{
+       writel(priv->enabled_irqs, priv->membase + UNIPHIER_FI2C_IE);
+}
+
+static void uniphier_fi2c_clear_irqs(struct uniphier_fi2c_priv *priv)
+{
+       writel(-1, priv->membase + UNIPHIER_FI2C_IC);
+}
+
+static void uniphier_fi2c_stop(struct uniphier_fi2c_priv *priv)
+{
+       dev_dbg(&priv->adap.dev, "stop condition\n");
+
+       priv->enabled_irqs |= UNIPHIER_FI2C_INT_STOP;
+       uniphier_fi2c_set_irqs(priv);
+       writel(UNIPHIER_FI2C_CR_MST | UNIPHIER_FI2C_CR_STO,
+              priv->membase + UNIPHIER_FI2C_CR);
+}
+
+static irqreturn_t uniphier_fi2c_interrupt(int irq, void *dev_id)
+{
+       struct uniphier_fi2c_priv *priv = dev_id;
+       u32 irq_status;
+
+       irq_status = readl(priv->membase + UNIPHIER_FI2C_INT);
+
+       dev_dbg(&priv->adap.dev,
+               "interrupt: enabled_irqs=%04x, irq_status=%04x\n",
+               priv->enabled_irqs, irq_status);
+
+       if (irq_status & UNIPHIER_FI2C_INT_STOP)
+               goto complete;
+
+       if (unlikely(irq_status & UNIPHIER_FI2C_INT_AL)) {
+               dev_dbg(&priv->adap.dev, "arbitration lost\n");
+               priv->error = -EAGAIN;
+               goto complete;
+       }
+
+       if (unlikely(irq_status & UNIPHIER_FI2C_INT_NA)) {
+               dev_dbg(&priv->adap.dev, "could not get ACK\n");
+               priv->error = -ENXIO;
+               if (priv->flags & UNIPHIER_FI2C_RD) {
+                       /*
+                        * work around a hardware bug:
+                        * The receive-completed interrupt is never set even if
+                        * STOP condition is detected after the address phase
+                        * of read transaction fails to get ACK.
+                        * To avoid time-out error, we issue STOP here,
+                        * but do not wait for its completion.
+                        * It should be checked after exiting this handler.
+                        */
+                       uniphier_fi2c_stop(priv);
+                       priv->flags |= UNIPHIER_FI2C_DEFER_STOP_COMP;
+                       goto complete;
+               }
+               goto stop;
+       }
+
+       if (irq_status & UNIPHIER_FI2C_INT_TE) {
+               if (!priv->len)
+                       goto data_done;
+
+               uniphier_fi2c_fill_txfifo(priv, false);
+               goto handled;
+       }
+
+       if (irq_status & (UNIPHIER_FI2C_INT_RF | UNIPHIER_FI2C_INT_RB)) {
+               uniphier_fi2c_drain_rxfifo(priv);
+               if (!priv->len)
+                       goto data_done;
+
+               if (unlikely(priv->flags & UNIPHIER_FI2C_MANUAL_NACK)) {
+                       if (priv->len <= UNIPHIER_FI2C_FIFO_SIZE &&
+                           !(priv->flags & UNIPHIER_FI2C_BYTE_WISE)) {
+                               dev_dbg(&priv->adap.dev,
+                                       "enable read byte count IRQ\n");
+                               priv->enabled_irqs |= UNIPHIER_FI2C_INT_RB;
+                               uniphier_fi2c_set_irqs(priv);
+                               priv->flags |= UNIPHIER_FI2C_BYTE_WISE;
+                       }
+                       if (priv->len <= 1) {
+                               dev_dbg(&priv->adap.dev, "set NACK\n");
+                               writel(UNIPHIER_FI2C_CR_MST |
+                                      UNIPHIER_FI2C_CR_NACK,
+                                      priv->membase + UNIPHIER_FI2C_CR);
+                       }
+               }
+
+               goto handled;
+       }
+
+       return IRQ_NONE;
+
+data_done:
+       if (priv->flags & UNIPHIER_FI2C_STOP) {
+stop:
+               uniphier_fi2c_stop(priv);
+       } else {
+complete:
+               priv->enabled_irqs = 0;
+               uniphier_fi2c_set_irqs(priv);
+               complete(&priv->comp);
+       }
+
+handled:
+       uniphier_fi2c_clear_irqs(priv);
+
+       return IRQ_HANDLED;
+}
+
+static void uniphier_fi2c_tx_init(struct uniphier_fi2c_priv *priv, u16 addr)
+{
+       priv->enabled_irqs |= UNIPHIER_FI2C_INT_TE;
+       /* do not use TX byte counter */
+       writel(0, priv->membase + UNIPHIER_FI2C_TBC);
+       /* set slave address */
+       writel(UNIPHIER_FI2C_DTTX_CMD | addr << 1,
+              priv->membase + UNIPHIER_FI2C_DTTX);
+       /* first chunk of data */
+       uniphier_fi2c_fill_txfifo(priv, true);
+}
+
+static void uniphier_fi2c_rx_init(struct uniphier_fi2c_priv *priv, u16 addr)
+{
+       priv->flags |= UNIPHIER_FI2C_RD;
+
+       if (likely(priv->len < 256)) {
+               /*
+                * If possible, use RX byte counter.
+                * It can automatically handle NACK for the last byte.
+                */
+               writel(priv->len, priv->membase + UNIPHIER_FI2C_RBC);
+               priv->enabled_irqs |= UNIPHIER_FI2C_INT_RF |
+                                     UNIPHIER_FI2C_INT_RB;
+       } else {
+               /*
+                * The byte counter can not count over 256.  In this case,
+                * do not use it at all.  Drain data when FIFO gets full,
+                * but treat the last portion as a special case.
+                */
+               writel(0, priv->membase + UNIPHIER_FI2C_RBC);
+               priv->flags |= UNIPHIER_FI2C_MANUAL_NACK;
+               priv->enabled_irqs |= UNIPHIER_FI2C_INT_RF;
+       }
+
+       /* set slave address with RD bit */
+       writel(UNIPHIER_FI2C_DTTX_CMD | UNIPHIER_FI2C_DTTX_RD | addr << 1,
+              priv->membase + UNIPHIER_FI2C_DTTX);
+}
+
+static void uniphier_fi2c_reset(struct uniphier_fi2c_priv *priv)
+{
+       writel(UNIPHIER_FI2C_RST_RST, priv->membase + UNIPHIER_FI2C_RST);
+}
+
+static void uniphier_fi2c_prepare_operation(struct uniphier_fi2c_priv *priv)
+{
+       writel(UNIPHIER_FI2C_BRST_FOEN | UNIPHIER_FI2C_BRST_RSCL,
+              priv->membase + UNIPHIER_FI2C_BRST);
+}
+
+static void uniphier_fi2c_recover(struct uniphier_fi2c_priv *priv)
+{
+       uniphier_fi2c_reset(priv);
+       i2c_recover_bus(&priv->adap);
+}
+
+static int uniphier_fi2c_master_xfer_one(struct i2c_adapter *adap,
+                                        struct i2c_msg *msg, bool stop)
+{
+       struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
+       bool is_read = msg->flags & I2C_M_RD;
+       unsigned long time_left;
+
+       dev_dbg(&adap->dev, "%s: addr=0x%02x, len=%d, stop=%d\n",
+               is_read ? "receive" : "transmit", msg->addr, msg->len, stop);
+
+       priv->len = msg->len;
+       priv->buf = msg->buf;
+       priv->enabled_irqs = UNIPHIER_FI2C_INT_FAULTS;
+       priv->error = 0;
+       priv->flags = 0;
+
+       if (stop)
+               priv->flags |= UNIPHIER_FI2C_STOP;
+
+       reinit_completion(&priv->comp);
+       uniphier_fi2c_clear_irqs(priv);
+       writel(UNIPHIER_FI2C_RST_TBRST | UNIPHIER_FI2C_RST_RBRST,
+              priv->membase + UNIPHIER_FI2C_RST);      /* reset TX/RX FIFO */
+
+       if (is_read)
+               uniphier_fi2c_rx_init(priv, msg->addr);
+       else
+               uniphier_fi2c_tx_init(priv, msg->addr);
+
+       uniphier_fi2c_set_irqs(priv);
+
+       dev_dbg(&adap->dev, "start condition\n");
+       writel(UNIPHIER_FI2C_CR_MST | UNIPHIER_FI2C_CR_STA,
+              priv->membase + UNIPHIER_FI2C_CR);
+
+       time_left = wait_for_completion_timeout(&priv->comp, adap->timeout);
+       if (!time_left) {
+               dev_err(&adap->dev, "transaction timeout.\n");
+               uniphier_fi2c_recover(priv);
+               return -ETIMEDOUT;
+       }
+       dev_dbg(&adap->dev, "complete\n");
+
+       if (unlikely(priv->flags & UNIPHIER_FI2C_DEFER_STOP_COMP)) {
+               u32 status = readl(priv->membase + UNIPHIER_FI2C_SR);
+
+               if (!(status & UNIPHIER_FI2C_SR_STS) ||
+                   status & UNIPHIER_FI2C_SR_BB) {
+                       dev_err(&adap->dev,
+                               "stop condition was not completed.\n");
+                       uniphier_fi2c_recover(priv);
+                       return -EBUSY;
+               }
+       }
+
+       return priv->error;
+}
+
+static int uniphier_fi2c_check_bus_busy(struct i2c_adapter *adap)
+{
+       struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
+
+       if (readl(priv->membase + UNIPHIER_FI2C_SR) & UNIPHIER_FI2C_SR_DB) {
+               if (priv->busy_cnt++ > 3) {
+                       /*
+                        * If bus busy continues too long, it is probably
+                        * in a wrong state.  Try bus recovery.
+                        */
+                       uniphier_fi2c_recover(priv);
+                       priv->busy_cnt = 0;
+               }
+
+               return -EAGAIN;
+       }
+
+       priv->busy_cnt = 0;
+       return 0;
+}
+
+static int uniphier_fi2c_master_xfer(struct i2c_adapter *adap,
+                                    struct i2c_msg *msgs, int num)
+{
+       struct i2c_msg *msg, *emsg = msgs + num;
+       int ret;
+
+       ret = uniphier_fi2c_check_bus_busy(adap);
+       if (ret)
+               return ret;
+
+       for (msg = msgs; msg < emsg; msg++) {
+               /* If next message is read, skip the stop condition */
+               bool stop = !(msg + 1 < emsg && msg[1].flags & I2C_M_RD);
+               /* but, force it if I2C_M_STOP is set */
+               if (msg->flags & I2C_M_STOP)
+                       stop = true;
+
+               ret = uniphier_fi2c_master_xfer_one(adap, msg, stop);
+               if (ret)
+                       return ret;
+       }
+
+       return num;
+}
+
+static u32 uniphier_fi2c_functionality(struct i2c_adapter *adap)
+{
+       return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm uniphier_fi2c_algo = {
+       .master_xfer = uniphier_fi2c_master_xfer,
+       .functionality = uniphier_fi2c_functionality,
+};
+
+static int uniphier_fi2c_get_scl(struct i2c_adapter *adap)
+{
+       struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
+
+       return !!(readl(priv->membase + UNIPHIER_FI2C_BM) &
+                                                       UNIPHIER_FI2C_BM_SCLS);
+}
+
+static void uniphier_fi2c_set_scl(struct i2c_adapter *adap, int val)
+{
+       struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
+
+       writel(val ? UNIPHIER_FI2C_BRST_RSCL : 0,
+              priv->membase + UNIPHIER_FI2C_BRST);
+}
+
+static int uniphier_fi2c_get_sda(struct i2c_adapter *adap)
+{
+       struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
+
+       return !!(readl(priv->membase + UNIPHIER_FI2C_BM) &
+                                                       UNIPHIER_FI2C_BM_SDAS);
+}
+
+static void uniphier_fi2c_unprepare_recovery(struct i2c_adapter *adap)
+{
+       uniphier_fi2c_prepare_operation(i2c_get_adapdata(adap));
+}
+
+static struct i2c_bus_recovery_info uniphier_fi2c_bus_recovery_info = {
+       .recover_bus = i2c_generic_scl_recovery,
+       .get_scl = uniphier_fi2c_get_scl,
+       .set_scl = uniphier_fi2c_set_scl,
+       .get_sda = uniphier_fi2c_get_sda,
+       .unprepare_recovery = uniphier_fi2c_unprepare_recovery,
+};
+
+static int uniphier_fi2c_clk_init(struct device *dev,
+                                 struct uniphier_fi2c_priv *priv)
+{
+       struct device_node *np = dev->of_node;
+       unsigned long clk_rate;
+       u32 bus_speed, clk_count;
+       int ret;
+
+       if (of_property_read_u32(np, "clock-frequency", &bus_speed))
+               bus_speed = UNIPHIER_FI2C_DEFAULT_SPEED;
+
+       if (bus_speed > UNIPHIER_FI2C_MAX_SPEED)
+               bus_speed = UNIPHIER_FI2C_MAX_SPEED;
+
+       /* Get input clk rate through clk driver */
+       priv->clk = devm_clk_get(dev, NULL);
+       if (IS_ERR(priv->clk)) {
+               dev_err(dev, "failed to get clock\n");
+               return PTR_ERR(priv->clk);
+       }
+
+       ret = clk_prepare_enable(priv->clk);
+       if (ret)
+               return ret;
+
+       clk_rate = clk_get_rate(priv->clk);
+
+       uniphier_fi2c_reset(priv);
+
+       clk_count = clk_rate / bus_speed;
+
+       writel(clk_count, priv->membase + UNIPHIER_FI2C_CYC);
+       writel(clk_count / 2, priv->membase + UNIPHIER_FI2C_LCTL);
+       writel(clk_count / 2, priv->membase + UNIPHIER_FI2C_SSUT);
+       writel(clk_count / 16, priv->membase + UNIPHIER_FI2C_DSUT);
+
+       uniphier_fi2c_prepare_operation(priv);
+
+       return 0;
+}
+
+static int uniphier_fi2c_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct uniphier_fi2c_priv *priv;
+       struct resource *regs;
+       int irq;
+       int ret;
+
+       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+       if (!priv)
+               return -ENOMEM;
+
+       regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       priv->membase = devm_ioremap_resource(dev, regs);
+       if (IS_ERR(priv->membase))
+               return PTR_ERR(priv->membase);
+
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0) {
+               dev_err(dev, "failed to get IRQ number");
+               return irq;
+       }
+
+       init_completion(&priv->comp);
+       priv->adap.owner = THIS_MODULE;
+       priv->adap.algo = &uniphier_fi2c_algo;
+       priv->adap.dev.parent = dev;
+       priv->adap.dev.of_node = dev->of_node;
+       strlcpy(priv->adap.name, "UniPhier FI2C", sizeof(priv->adap.name));
+       priv->adap.bus_recovery_info = &uniphier_fi2c_bus_recovery_info;
+       i2c_set_adapdata(&priv->adap, priv);
+       platform_set_drvdata(pdev, priv);
+
+       ret = uniphier_fi2c_clk_init(dev, priv);
+       if (ret)
+               return ret;
+
+       ret = devm_request_irq(dev, irq, uniphier_fi2c_interrupt, 0,
+                              pdev->name, priv);
+       if (ret) {
+               dev_err(dev, "failed to request irq %d\n", irq);
+               goto err;
+       }
+
+       ret = i2c_add_adapter(&priv->adap);
+       if (ret) {
+               dev_err(dev, "failed to add I2C adapter\n");
+               goto err;
+       }
+
+err:
+       if (ret)
+               clk_disable_unprepare(priv->clk);
+
+       return ret;
+}
+
+static int uniphier_fi2c_remove(struct platform_device *pdev)
+{
+       struct uniphier_fi2c_priv *priv = platform_get_drvdata(pdev);
+
+       i2c_del_adapter(&priv->adap);
+       clk_disable_unprepare(priv->clk);
+
+       return 0;
+}
+
+static const struct of_device_id uniphier_fi2c_match[] = {
+       { .compatible = "socionext,uniphier-fi2c" },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, uniphier_fi2c_match);
+
+static struct platform_driver uniphier_fi2c_drv = {
+       .probe  = uniphier_fi2c_probe,
+       .remove = uniphier_fi2c_remove,
+       .driver = {
+               .name  = "uniphier-fi2c",
+               .of_match_table = uniphier_fi2c_match,
+       },
+};
+module_platform_driver(uniphier_fi2c_drv);
+
+MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
+MODULE_DESCRIPTION("UniPhier FIFO-builtin I2C bus driver");
+MODULE_LICENSE("GPL");